ArthurEld,
Yes, I have a lot going on. The main reason I am working on having a PLC (programmable logic controller) talk to my Schneider XW-Pro inverter is so that I can have it properly change modes between charging when the solar is making extra power, and invert from batteries to help reduce how much power I use from the grid during the evening peak rate time of use which is from 4 to 9 pm here with SCE. The real problem (in my opinion) is a programming error by Schneider. With the settings I am using now, it all works, except I need to change two values to force it to either charge or discharge based on the battery voltage. If the voltage is above the two numbers, it will only discharge/invert, and if the battery voltage is above the two numbers, it will only charge. These numbers should be time dependent when it is blocking charging or blocking grid power output, it should ignore that value, but it does not. If the battery is below the recharge volts, even if charging is blocked, it can't go into invert, and if the battery voltage is above the grid support voltage, it can't go into charge, even if grid support is blocked by time. So my step one is just having the PLC change those values based on time of day to make it charge when my solar is producing, and invert during peak time.
Once I get that part working, I can add more functions. I can actually read how much power is being produced and used and adjust the charge rate and grid sell power numbers to "Flatten the curve" to use as little grid power as possible while not exporting power to the grid to keep it in the battery. If I ever do find the details of the JK BMS RS-485 data, I could also add that and have the PLC report the state of charge and such, but that would be much further down the road.
svetz, Ampster,
Yes, this heat wave is crazy. The good thing is that the weather has been predicted a week in advance, so people have been prepared for it. The "Lake Fire" is "under control", Castaic Lake even opened the beaches. We have a few other small firs in a 30 mile radius, but nothing too serious right now. There is a bit of smoke and haze and air quality is rated as poor/unhealthy. And I have more soot and ash on my solar panels again.
They did manage to keep the grid power up last night. I am sure they had to crank up some "peaker plants" and maybe dump some resevoir water down through turbines to make it up, but the grid held on to run all the A/C running in the valley as the thousands of solar grid tie systems went offline about 7 pm last night with the outside temp still over 105F. I did what I could, I pushed over 8 KWH's out of my battery as the sun dipped and kept my draw from the grid down to under 3 KW's all night. Without the battery, it would have been pulling over 5 KW's to keep the A/C blowing cold.
To zero out my grid with the A/C running, I would need about double my battery capacity. The Schneider inverter will take it. But to move that much power safely, I would certainly have to have a WattNode reading my grid current and carefully adjusting the export current as the A/C compressor cycles. The 3,600 watt swing is more than I should be exporting, so when it stops, I need to back off the inverter very quickly.
Obviously my current 16 solar panels can't make enough power on their own to make that back up, but I could have the batteries charging from grid at a slow rate all night long and not increase my purchased power. But by the letter of the NEM 2.0 agreement, grid power can't be used to charge and sell back to the grid. BUT... If I don't export any power and it is all used to run my home, I am not violating the rules. And in many ways, I am helping the utility by using extra power when demand is low and not taking power when the demand is high. They certainly should not complain, and hopefully in the future, we will get credit for doing our part to help the grid. I have room to add about 6 more solar panels fairly easily. But even that can't keep my whole home A/C alive in these crazy heat conditions. 2 days ago, the latest I have from SCE, it did top 100, but not like yesterday, and even with my solar making 24 KWH's, I still had to buy 50 KWH's from SCE. That would take a serious 12.5 KW solar array to make 74 KWH's of power in 6 sun hours. I just need 200% more panels. I could cut my consumption a little if I had to, but not that much. And before anyone starts whining, my thermostat was up to 80. With it being over 110 outside, the indoor house temp went up 2 degrees with the A/C running flat out. I have excellent thermal insulating windows and doors, and the attic and walls are well insulated too. This kind of heat is no joke. Even for being halfway between Hollywood and the Mojave Dessert, this is not normal. We only get conditions like this a few days a year. But when they do come, you have to be ready for it. It is a "Dry Heat" so it may not feel quite as bad as 100 back north of Chicago, but it still feels wrong. The inside of my garage did get to 100, but I had to shut off my vent fan, as that made it worse fast as the air exhausted was being replaced by the even hotter air outside. Same with the attic fans. Mine normally turn on at 90 degrees, but it makes them pull in 115 air! So another future project will be adding smart control to only run the attic and garage fans when they are actually hotter than the outside air. Not just on inside heat alone.
